1 Massa - Parākramabāhu I

Parākramabāhu I ruled from Polonnaruwa during what is considered the last great consolidation of Sinhalese power in medieval Sri Lanka, unifying three fractious kingdoms by 1153 after decades of civil conflict. His reign funded massive irrigation works — the Parakrama Samudra reservoir remains one of the largest ancient man-made bodies of water in the world — and a coinage that circulated through a genuinely monetized agrarian economy, not merely as ceremonial issue.

The massa denomination derives from the ancient Indian māṣa weight standard, its persistence into 12th-century Ceylon reflecting deep subcontinental commercial ties that outlasted any single political authority.